\begin{tikzpicture}
	\tkzDefPoints{0/0/O, 1.5/0/x}
	\tkzDrawLine[add=1.0 and 0](O,x)
	\tkzLabelLine[pos=1.0,right](O,x){$l$}
	\tkzDrawPoints[fill=black](O)
	\tkzLabelPoints[above](O)
\end{tikzpicture}

